Lifting-jack



J. W. ALFRED. LIFTING JACK.

(No Model.)

No. 461,880. Patented Oct. 27, 1891.

tending throughout the entire length of the UNITED STATES PATE TOFFiCfie JAMES V. ALFRED, OF PITTSBURG, PENNSYLVANIA.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 461,880, dated October2'7, 1891.

Application filed December 4, 1890.

T0 aZZ whom, it may concern.-

Be it known that I, JAMES W. ALFRED, a citizen of the United States,residing at Pittsburg,in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inLifting-Jacks; and I do declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to the letters of referencemarked thereon, which form a part of this specification.

This invention relates to certain new and useful improvements inlifting-jacks.

The invention consists in the peculiar construction and in the novelcombination, arrangement, and adaptation of parts, all as more fullyhereinafter described, shown in the accompanying drawings, and thenspecifically definedin the appended claims.

The invention is clearly illustrated in the accompanying drawings,which, with the letters of reference marked thereon, form a part of thisspecification, like letters of reference indicating like partsthroughout the several views, and in which drawings Figure l is a sideview of a lifting-jack constructed in accordance with my invention. Fig.2 is a side view of the operating mechanism,the same being shown upon anenlarged scale. Fig. 3 is a front sectional view of the same, and Fig. tis a horizontal section upon the line 00 (I; of Fig. 3. Fig. 5 is anenlarged detail in perspective of the operating-cams.

Reference now being had to the details of the drawings by letter, Arepresents the standard, which is made of cast-iron and is provided witha suitable base portion A, said base portion being cast integral withthe standard and may be of any convenient or desired size or form. Thestandard A is provided with a central longitudinal opening B, ex-

standard, said central opening being preferably rectangular incross-section, and within this opening is placed the lifting-bar O,which is provided at its upper end with a bearingblock 0, and at itslower end a horizontal lug orextension C is provided,which lug isadapted to project through a vertical slot 0 pro- Serial No. 373,560.(No model.)

operating hand-lever is pivoted on the oppo-" site side of the jack.

The vertical face of the lifting-bar 0 upon the side opposite to thatprovided with the lug C is provided with a series of notches,

with which the hereinafter-described mechanism for moving and regulatingthe movements of the said lifting-bar engage in operating the device.

D is a casting which forms the inner end of the operating-lever. Thiscasting is provided at one of its ends with a socket to receive thehandle-bar D, and at its opposite end is composed of twolongitudinally-projecting arms D which have between them two eccentricsd and cl, the whole being of such width as will adapt it to be fitted ina vertical recess A provided in the front face of the extension A in theupper portion of the standard.

The casting D, carrying at its inner end the arms D and eccentrics d andcl, is pivotally connected with the standard A by means of a pivot (1passed through the enlarged portion A of the standard, and the arms Dand eccentrics (Z and (1 at the pointsa't which said eccentrics unitewith the arms D In an offset in the standard B and in the lever D areformed the seats or recesses d? to receive the eccentrics d and d.

E and E are the dogs or latches carried by the eccentrics. One of saidlatches or dogs is adapted to normally rest within the notches in theface of the rack-bar O. In this connect-ion I wish to call particularattention to the forms of the latches E and E and their connection withthe eccentrics and to the points at which said eccentrics are pivotedwith reference to the bodies of the latches, as in the peculiarconstruction and arrangement of these parts resides the essentialfeature of the present invention.

It will be observed upon reference to the drawings that the bodies ofthe latches E and E are heavy, and that when in their places they areslightly inclined from a vertical position. This inclination, althoughslight, should be sufficient to at all times insure their being kept inplace by gravity. The latches have attached to their bifurcated portionsstraps ofmetal d which pass around the eccentrics cl and d and whichserve to prevent the latches from becoming detached therefrom. Theseeccentrics are so arranged with reference to each other on the pivotthat the greatest possible amount of power is obtained as the liftingforce is applied in a direct line from the pivotal center to the pointat which the power is imparted to the rackbar. It will also be seen thatwhen one of the latches is passing upward the other is going down, owingto their position on opposite eccentrics. 1

The latches E and E are adapted by reason of the step-like form of theirfree ends to alternately engage each with two teeth of the rack-bar,thus giving greater security against breakage and distributing thestrain more evenly. The latch or dog E is provided with alaterally-projecting shoulder e, which overlaps the shorter latch or dogE and provides a wider bearing-surface to engage with the rack-bar 0while latch E, which is shorter than latch E, and consequently engagesthe rack-bar C at a point lower down than that at which the latterengages it, also has a laterally-projecting shoulder c.

The plate F is pivoted in a projection from the side of the standard Aand works against the lower surface of the latch E and the shoulder e ofthe latch E and is pressed against the said sides bya coiled spring F,which is attached to a projection f. (See Fig. 4.) A thumb-latch fprojects on the outside of the standard, the shaft of which latch passesthrough the standard .and between the plate F and the dog or latch'E outof normal contact with the latches E and E; but when the thumb-latchf isturned so that its greatest diameter will be perpendicular to thespringF the latches will fall of their own weight on the rack-bar, andwhen the lever is moved either up or down one of the latches in itsascent will catch in the teeth of the rack-bar and raise it.

Near the upper end of the plate F is a pin f which passes through theside of the standard and is adapted to either project inside of thestandard and engage the front side of the plate F or to be drawn backout of engagement with the same. A coiled spring f through which the pinpasses, presses it normally outward and holds it out, so that to use thepin the operator has simply to press it in, when it will engage with theplate F and, holding the latter back, also hold back the latches E andE, which bytheir disengagement with the rack-bar will allow the same todrop to the ground.

It will be readily seen how by the turning of the thumb-latch to eithera horizontal or vertical position and the alternate movement of the twolatches up ordown the rack-bar is either raised or lowered.

Having thus described my invention, what I claim to be new, and desireto secure by Letters Patent, is

1. The combination, with the standard, movable racked lifting-bar, and aplurality of eccentrically-pivoted latches on the same pivot and adaptedto engage the toothed side of the. rack-bar, one above the other, andmechanism for operating the latches, of a spring adapted to hold thelatches out of engagement with the lifting-bar during their upwardmovement, substantially as and for the purpose specified.

2. In a lifting-jack, the combination of the standard, the movableracked lifting-bar,and two actuating-latches on a common pivot, thespring-plate and the pin engaging the same and. adapted tosimultaneously hold all of the latches out of engagement with the rackof the lifting-bar during the downward movement of said bar,substantially as and for the purpose-described. I

In testimony whereof Iaffix my signature in presence of two witnesses.

JAMES W. ALFRED. lVitnesses:

W. J. 3V. CovDEN, GUY R. O. ALLEN.

